1. Field of the Invention
The present invention relates to an electroconductive resin composition having excellent antistatic and electroconductive properties, processability, and thermal resistance. Molded articles and coatings manufactured from the electroconductive resin composition exhibit increased resistance to bleeding.
2. Description of Related Art
A polyphenylene ether resin is a thermoplastic resin having excellent mechanical properties, thermal resistance and dimensional stability.
However, use of polyphenylene ether resin alone results in articles having unacceptable impact strength and solvent resistance. Furthermore, polyphenylene ether resin has a high melt viscosity which results in an undesirable processability. Heretofore, the processability has been improved by blending the polyphenylene ether resin with a flowability improving agent or with a polystyrene resin, which is compatible with the polyphenylene ether resin. The processability, however, is still inadequate, even with the use of a flowability improving agent or a polystyrene resin.
The processing temperature of conventional polyphenylene ether resin compositions are generally 240.degree. C. to 350.degree. C. Molded articles made from these compositions exhibit problems with the flowability improving agent causing bleeding on the surface thereof, especially in the case of a processing at a high temperature.
Furthermore, many polyphenylene ether resin compositions are non-electroconductive and therefore cannot be used as an antistatic coating on a molded article unless the article is first undercoated with electroconductive primers, or electroconductive particles, flakes, fibers, such as electroconductive carbon blacks.
Demand for developing materials having resistance to bleeding, excellent heat resistance, dimensional stability, antistatic properties, and electroconductive properties, in electric and electronics fields has increased recently.